Transverse watercraft propeller

ABSTRACT

A new type of propeller with a transverse driving shaft can be mounted on an outboard internal combustion engine instead of a conventional screw type propeller or disposed directly on the transom of a boat. The propulsion thrust is generated by flat propeller blades mounted on planetary gearboxes and rotated simultaneously around two perpendicular intercrossed axes of rotation. Such double rotation causes the blades to move along the specific curved paths and to generate virtually permanent and effective propulsion thrust for propelling watercraft. Both sides of the propeller blades are used as working surfaces. Unlike the conventional screw type propeller, a new propeller can be disposed not only under the water but also over the water with the blades extending into the water during their rotations for propelling the boat. Such propulsion apparatus can be specifically useful for propelling different types of watercraft in shallow water and other situations when a conventional screw propeller can be easily damaged. The propeller can be rotated not only by an internal combustion engine but also by a electric power any other type of drive.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application is a continuation-in-part of applicationSer. No. 10/309897 filed on Dec. 5, 2002 which is a continuation-in-partof application Ser. No. 10/093731 filed on Mar. 11, 2002 which is acontinuation-in-part of International application PCT/US01/16526 filedon Jul. 17, 2001, now International Publication (PCT) No. WO 02/08054A1, which was published under PCT Article 21(2) in English.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates generally to improvements in propellersystems for developing a propulsive force, and more particularly, itpertains to a new method and apparatus for propelling watercraft, suchas boats, ships, ferries, rafts, fish-boats, dredges, tankers,tug-boats, etc.

[0004] 2. Description of the Prior Art

[0005] Nowadays, the most common means for propelling watercraft are thescrew type propellers which are mounted on the diving shafts disposedalong the advancement direction of the watercraft. They displace thewater backward as a result of orientation of the propeller blades withangles of incident relative to the advancement direction of thewatercraft. That is why only the rearward component of the velocity ofthe water that is accelerated by the action of a screw propellercontributes to the desired thrust. A spinning screw propeller imparts asubstantial outward radial velocity to water and the energy expended incausing this outward radial motion is wasted on rotation of water withformation of water disturbances such as visible wakes, vortices,cavitation, etc. That is why the thrust actually developed by the screwpropellers is far less than the amount that should be available from theshaft horsepower that creates it.

[0006] To improve such disadvantageous aspects of the screw propellers,various propulsion apparatus have been developed throughout the yearswhich have transversely disposed axes of rotations of the blades(vertical or horizontal) for developing more effective propulsion forcewith lower speed of rotation. Numerous patents and researches have beendevoted to development of propeller systems wherein the propeller bladesare pivoted simultaneously with rotation of the driving shaft and to theproblem of optimizing the cyclic variations of the orientation ofindividual blades. Some of such systems utilize rotation of propellerblades or paddles not only around the axis of the driving shaft but alsoaround complementary axes of rotation. The basic concept presented inthese systems is that the usable propulsive force is developed as aresult of rotating the blades around two axes of rotation with variableorientation of the rotated blades relative to the driving shaft.

[0007] Propulsion apparatus are known (U.S. Pat. No. 1,284,282 toFitzpatrick, U.S. Pat. No. 1,450,454 to Roney, U.S. Pat. No. 1,667,140to Clark, U.S. Pat. No. 1,923,249, to Abram) wherein blades offeathering type extend radially from the driving shaft and are rotatedaround radial axes simultaneously with rotation of the driving shaft. Inthe paddling position, the blades are held in a plane parallel to theaxis of the driving shaft and in the feathering position, the blades areheld in a plane perpendicular to the axis of the driving shaft. Aserious drawback of such systems is that, in the process of changingfrom one position to the other, the blades have to be rotated 90 degreesaround their longitudinal axes with a considerable resistance of thefluid and low paddling and propulsion efficiency during such rotation.

[0008] There are also known propulsion apparatus wherein the propellerblades are oriented and rotated in the planes parallel to the drivingshaft (U.S. Pat. No. 3,270,820 to Frazier, British patent No. 217,223 toPensovecchio). Although having advantages in respect to the propellerswith feathering blades, such apparatus with only two blades mounted in aplane perpendicular to the propeller shaft also have low efficiency andirregular power consumption. Different combinations of such propulsionapparatus are cumbersome and the mechanisms employed to effect theiroperations is complicated. For these reasons, a limited practicalsuccess has been obtained by such type of apparatus.

[0009] Another disadvantage of the conventional screw propellers istheir vulnerability to underwater impact and damage when they are usedin shallow water or in situations when there are different kinds ofsubmerged debris such as tree logs, limbs, etc. Furthermore, thesubmerged screw propeller acts as a drag, considerably slowing thewatercraft.

[0010] To solve this problem, the screw propeller can be mounted on thewatercraft in such a position that a portion of the propeller bladesrotate out of the water, as described, for example, in U.S. Pat. No.5,807,151 to Sumino. However, such a mounting of the screw propellersconsiderably reduces their propulsion efficiency. As a result, the usageof such water surface-piercing screw propellers remains restricted.

[0011] Different types of paddle-wheels which are used for propellingwatercraft in shallow water or in the water containing dangerous debris,as disclosed, for example, in U.S. Pat. No. 6,264,518 to Price and U.S.Pat. No. 6,447,352 to Nuss, also provide very low propulsion efficiency,speed and maneuverability for the watercraft.

[0012] The present invention seeks to overcome the deficiencies of knownpropulsion systems and to benefit from the advantages that may beexpected from the new method and apparatus.

[0013] The object of the invention is to provide a reliable propellingapparatus with improved propulsion efficiency which can be mounted onthe conventional outboard internal combustion engines or disposeddirectly on the transom of a boat. It can be used for propellingdifferent types of the watercraft not only in the deep water, but alsoin the shallow water or other situations with possibility of damagingthe propeller.

BRIEF SUMMARY OF THE INVENTION

[0014] The invention is based on my discovery that an effectivepropulsive force in a liquid fluid can be developed as a result ofrotation of three, four, six or more substantially flat propeller bladesor other similar propelling means simultaneously around at least twoperpendicular axes with the same speed. One of these axes of rotation isdisposed transversely to the advancement direction of the watercraft,preferably horizontally or vertically. The other one or more axes ofrotation are disposed radially to that first transverse axis and arerotated together with the propeller blades in planes perpendicular tothe transverse axis. The propeller blades are balanced relative to theaxes of rotation and can be rotated simultaneously around thatperpendicular axes without interfering with each other. During thatrotations, the substantially flat surfaces of each propeller blades areoriented in the planes of rotation around the radial axis or disposed atacute angles with that planes. Preferably, the propeller blades haveairfoil cross-sections in these planes.

[0015] In a preferred embodiment of the propulsion apparatus, one, twoor more planetary gearboxes are fixed on a driving shaft or mounted on asupport rod with ability to be rotated around their axes disposedtransverse to the advancement direction of the watercraft. Two, three orfour propelling means are mounted rotatably on each of the planetarygearbox. Each of the propelling means includes a substantially flatpropeller blade which is balanced relative to the radial axis ofrotation by a counter-weight. The propelling means are mounted on theradial output shafts of the planetary gearboxes and disposedperpendicular to the axes of these radial output shafts. Each propellingmeans extends in two opposite directions from a radial output shaft withits center of gravity disposed on the axis of that shaft.

[0016] The propelling means are constrained by the planetary gearengagements to rotate around the axes of the radial output shafts of theplanetary gearboxes simultaneously with the rotation around the axis ofthe driving shaft or the support means. The planetary gearboxes can berotated by an internal combustion engine, an electric motor or any othertypes of drive.

[0017] The propulsion apparatus can be mounted on a conventionaloutboard engine or directly on the transom of a watercraft. Unlikeconventional screw type propellers, the rotated planetary gearboxes withpropelling means can be disposed not only under the water level but alsoover the water level because the propulsion thrust is developing by thepropeller blades which extend substantially downwards. The disposing ofthe planetary gearboxes above the water surface eliminates its draggingin the water during the movement of the watercraft and improves thereliability of oil sealing elements and other details. Such propulsionapparatus can be particularly useful for propelling any existing orspecially designed watercraft in shallow water or in the othersituations when a conventional screw propeller can be easily damaged.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] A propulsion apparatus and other objectives of the presentinvention will become apparent from the following description taken inconjunction with preferred embodiments thereof with reference to theaccompanying drawings, in which:

[0019] FIGS. 1 is a schematic perspective view of the preferredembodiment of the propulsion apparatus mounted on a outboard engine.

[0020]FIG. 2 is a partial vertical cross-sectional view along line II-IIin FIG. 1.

[0021]FIGS. 3a, 3 b, 3 c, 3 d are cross-sectional views along lineIII-III in FIG. 2 with different angle positions of the rotatedplanetary gearbox.

[0022]FIGS. 4a, 4 b are schematic perspective views of anotherembodiment of the propulsion apparatus mounted on a outboard engine withdifferent angle positions of the rotated planetary gearboxes.

[0023]FIG. 5 is a partial vertical cross-sectional view along line V-Vin FIG. 4a.

[0024]FIG. 6 is a vertical cross-sectional view along line VI-VI in FIG.5.

[0025]FIG. 7 is a vertical cross-sectional view along line VII-VII inFIG. 5.

[0026]FIG. 8 is a schematic perspective view of an embodiment of thepropulsion apparatus mounted on the transom of a watercraft.

[0027]FIG. 9 is a horizontal cross-sectional view along line IX-IX inFIG. 8.

[0028]FIG. 10 is a vertical cross-sectional view along line X-X in FIG.8.

[0029]FIG. 11 is a vertical cross-sectional view along line XI-XI inFIG. 8.

[0030] The identical details in all the drawings have the samedesignations.

DETAILED DESCRIPTION OF THE INVENTION

[0031] Referring now to FIGS. 1, 2 and 3 a, an outboard internalcombustion engine 10 is mounted in a conventional manner on the transom11 of a watercraft 12 with ability to be pivoted around a vertical axis13 and a horizontal axis 14. A gearbox 15 mounted on the engine caseextension 16 encloses a conventional bevel gear drive including a pinionbevel gear 17 which is fixed on the engine shaft 18 and is engaged withone of two driven bevel gears 19 or 20. A horizontal driving shaft 21 ismounted in the bearings 22 and 23 and is disposed transverse to theadvancement direction of the watercraft 12. The bevel gears 19, 20 arekeyed on the driving shaft 21 so that they can be moved along its axisto engage or disengage with the pinion bevel gear 17 for changing thedirection of rotation of the driving shaft 21.

[0032] Two identical planetary gearboxes 24 and 25 are mounted on bothsides of the gearbox 15. According to the preferred embodiment of thisinvention, each of the planetary gearbox has a cylindrical housing 26with a central hub 27 which is fixed on the horizontal shaft 21. A cover28 is secured to the cylindrical housing 26 by fasteners (not shown) andis mounted rotatably on the extension 29 of the gearbox 15. There is asealing element 30 between the cover 28 and the extension 29. Each ofthe planetary gearboxes 24, 25 encloses a planetary bevel gearengagement comprising a sun bevel gear 31 which is fixed on theextension 29 and three identical planet bevel gears 32, 33, 34 which arefixed on three radial output shafts 35, 36 and 37, respectively. Each ofthe planet bevel gears 32, 33, 34 is engaged with the sun bevel gear 31at right angle with a one-to-one ratio. The radial output shafts aredisposed substantially 120 degrees from each other. Each radial outputshaft is mounted in two bearings 38 and 39 which are mounted in thehousing 26 and on the central hub 27, respectively. The radial outputshafts 35, 36, 37 extend out of the planetary gearbox through sealingelements 40. Three propelling means 41, 42 and 43 are affixed to theends of the radial output shafts 35, 36, 37, respectively. They aredisposed perpendicular to the axes of the radial output shafts andextend in two opposite directions from that shafts. Each of thepropelling means 41, 42, 43 includes a propeller blade 41 a, 42 a or 43a which is balanced by one of the counter-weights 41 b, 42 b or 43 brelative to one of the axes of the radial output shafts 35, 36, 37,respectively. The centers of gravity of the propelling means 41, 42, 43are disposed on the axes of the radial output shafts 35, 36, 37,respectively. Three propeller means 41, 42, 43 disposed 120 degrees fromeach other are also balanced relative to the axis of the driving shaft21.

[0033] The propeller blades 41 a, 42 a, 43 a are substantially flat andare disposed in the planes of rotations around the radial output shafts35, 36, 37, respectively, or at acute angles “a” with that planes.Preferably, they have airfoil cross-sections in these planes to reduce aresistance in the water during rotations around the radial outputshafts. The gearbox 15 and the planetary gearboxes 24, 25 can be filledwith a lubricating oil.

[0034] Those skilled in the art understand that the engine caseextension 16 can be of any desired shape and size and the gearbox 15 canbe mounted on that case extension at such a height that the drivingshaft 21 and the planetary gearboxes 24, 25 will be disposed under thewater level or over the water level.

[0035] In the operation, the planetary gearboxes 24, 25 are rotated bythe driving shaft 21 in the direction of arrow R. Simultaneously withrotating around the axis of the transverse horizontal driving shaft 21,the propelling means 41, 42, 43 are constrained by the planetary gearengagements of the planetary gearboxes 24, 25 to rotate around the axesof the radial output shafts 35, 36, 37 with the same rotational speed.As a result of such double rotations, the propeller blades 41 a, 42 a,43 a follow specific curved paths. In the positions when the propellerblades 41 a, 42 a, 43 a are moving backward from the stern of thewatercraft they extend substantively downwards and are orientedsubstantially perpendicular to this movement. Simultaneously, thepropeller blades 41 a, 42 a, 43 a are moving sideward relative to theadvanced direction of the watercraft. As a result, a propulsion forcefor propelling the watercraft is developing. Both sides of eachpropeller blade are used consecutively as working surfaces for exertingthe propulsion strokes during each turn of the driving shaft. During therotations, radial extensions and circumferential velocities of thepropeller blades relative to the axis of the driving shaft 21 arechanging. As a result, the propeller blades are accelerated anddecelerated which produces an additional propulsion effect.

[0036] When the propeller blades are moving in the advancement directionof the watercraft, they are oriented substantially in th plane of suchmovement with minimum resistance in the water and with reducedcircumferential velocity around the driving shaft 21. The efficiency ofthe propulsion thrust developed in different angle positions of therotated planetary gearboxes depends on the orientations of the propellerblades relative to the axes of the driving shaft 21 and relative to theadvancement direction of the watercraft 12. The propulsion force isdeveloping by the propeller blades when they extend substantiallydownwards, oriented substantially perpendicular to the advancementdirection of the watercraft and are moving backwards relative to thatdirection. If the driving shaft and the planetary gearboxes are disposedover the water level, the propeller blades are plunged into the water inthese positions. The sideward movement of the propeller blades relativeto the advancement direction of the watercraft also contribute to thedevelopment of the propulsion force.

[0037] Virtually no propulsion force is developing by the propellerblades when they are parallel to the axis of the driving shaft 21because at such positions the propeller blades are moving in theadvancement direction of the watercraft and are oriented so that haveminimum resistance and relatively low speed in the water. If the drivingshaft 21 and the planetary gearboxes are disposed over the water levelthe propeller blades which are parallel to the driving shaft are alsodisposed over the water level.

[0038] In order to facilitate the understanding of the development ofthe propulsion force, the movement of the propeller blades is explainedwith references to FIGS. 3a, 3 b, 3 c, 3 d which illustrate thepositions of the planetary gearbox 24 after each 30 degrees rotations inthe direction of arrow R around the axis of the driving shaft 21. Duringeach of these rotations, the propelling means 41, 42, 43 have alsorotated 30 degrees clockwise around the radial output shafts.

[0039] The position shown in FIG. 3a corresponds to the position of theplanetary gearbox 24 in FIGS. 1 and 2 when the propelling means 41 is inthe upper part of the planetary gearbox 24 and is oriented parallel tothe axis of the driving shaft 21. The propeller blade 41 a extends inthe direction opposite to the gearbox 15 and is moving along the arrow A(in FIG. 1) in the advancement direction of the watercraft beingoriented so that it has minimum resistance in the water.

[0040] Two other propeller blades 42 a and 43 a extend substantiallydownwards because the propelling means 42, 43 are inclined only 30degrees from the vertical directions being disposed on the ends of theradial output shafts 36, 37 which are, in this position, turned 30degrees down from the horizontal positions. As a result of rotation ofthe planetary gearbox 24, the propeller blades 46, 47 are movingbackwards from the stern of the watercraft along the arrow B beingoriented substantially perpendicular to this direction. The propellerblades 42 a, 43 a are also moving sidewards in opposite directions alongthe arrows C, D with minimum resistance in the water to such sidewardmovements. The propulsion force is exerted as a result of such a combinemovement of the propeller blades.

[0041] To prevent the possibility of interfering in such positions ofthe planetary gearboxes, the propeller blades can be disposed at acuteangles “α” with the planes of rotation around the radial output shafts.The propeller blades 42 a and 43 a can be parallel to each other in thisposition of the planetary gearbox if the angles “α” are about 25-28degrees.

[0042] In the position shown in FIG. 3b, the propelling means 42 extendsvertically downwards. As a result of rotating by the driving shaft 21,the propeller blade 42 a is caused to move backward from the stern ofthe watercraft being oriented substantially perpendicular to thedirection of this movement. Simultaneously, the propeller blade 42 a ismoving sideward because it is rotated around the radial output shaft 36.As a result, an effective propulsion force for propelling the watercraftis developing.

[0043] The other two propelling means 41, 43 are inclined only 30degrees from their positions parallel to the driving shaft 21 and themovement of the propeller blades 41 a, 43 a in this position virtuallydo not have a considerable influence over the developing the propulsionforce. If the planetary gearboxes are disposed over the water level, thepropeller blades 41 a, 43 a in this position are also disposedsubstantially over the water level.

[0044] In the position of FIG. 3c, which corresponds to a mirrorposition of the planetary gearbox 25 in FIGS. 1 and 2, the propellingmeans 43 is disposed in the lower part of the planetary gearbox and isoriented parallel to the driving shaft 21. The propeller blade 43 aextends toward the gearbox 15 and is moving along the advancementdirection of the watercraft with minimum resistance in the water. Asshown in FIGS. 1 and 2, the propeller blades in such positions can passunder the gearbox 15 without interfering with it if the planetarygearboxes 24, 25 are mounted in close proximity to the gearbox 15.

[0045] Two propelling means 41, 42 extend substantially downward in thisposition. As a result of the rotation around the axis of the drivingshaft 21, the propeller blades 41 a, 42 a are moving substantiallybackward from the stern of the watercraft. The blades are oriented atsome angles with the direction of their backward movements.Nevertheless, they are capable to exert the propulsion force. However,in such positions the efficiency of the developing propulsion force isthe lowest in compare with the other angle positions of the rotatedplanetary gearboxes. If the driving shaft 21 and the planetary gearboxes24, 25 are mounted over the water level, the propeller blades can alsobe disposed in this position substantially over the water level.

[0046] In the position of FIG. 3d, the propelling means 41 extendsvertically downwards. The propeller blade 41 a is moving backwards fromthe stern of the watercraft as a result of rotation around the drivingshaft 21 being substantially perpendicular to such direction and exertsan effective propulsive force, while the propeller blades 42 a, 43 a arein the positions when they virtually do not influence considerably onthe development of the propulsion force.

[0047] After turning of the planetary gearbox next 30 degrees from theposition of FIG. 3d, the propeller blades will be in the positionssimilar to their positions shown in FIG. 3a and the described movementof the propeller blades will repeat during all the rotation of thedriving shaft 21.

[0048] A propulsion thrust for propelling the watercraft is developingvirtually in any angle position of the planetary gearbox. However, theefficiency of the propulsion thrust in different positions depends onthe orientation of the propeller blades at that moment. However, thoseknowledgeable in the art will understand that with two planetarygearboxes 24 and 25 rotated simultaneously, it is possible to adjusttheir angle positions relative to each other on the driving shaft 21, sothat six propeller blades 41 a, 42 a, 43 a, 41 a′, 42 a′, 43 a′ canexert the propulsion strokes consecutively. When one of the planetarygearboxes is in a position with the propeller blades developing themaximum propulsion force, the other one can be in a position wherein thelowest propulsion force is developed. As a result, a virtually permanentpropulsion thrust for propelling a watercraft can be developed with thesubstantially equalized power consumed by the engine 10.

[0049]FIGS. 4a, 4 b, 5, 6 and 7 illustrate another embodiment similar tothe described propulsion apparatus but having only two propelling meansmounted on each planetary gearbox. An internal combustion engine 10having the engine case extension 16 and the gearbox 15 is mounted on thetransom 11 of a watercraft 12 as previously described. Two planetarygearboxes 44 and 45 are mounted on the gearbox 15. In FIGS. 4a and 4 bthey are shown in two angle positions turned 90 degrees from oneposition to another. As shown in FIGS. 5-7, each planetary gearbox has acylindrical housing 46 with a central hub 47 and a cover 48 and enclosestwo radial output shafts 49, 50 disposed along a common axisperpendicular to the driving shaft 21. Each radial output shaft ismounted in two bearings 51, 52 and extends out of the planetary gearboxthrough a sealing element 53. The planetary bevel gear engagement ineach planetary gearbox 44 and 45 includes a sun bevel gear 54 fixed onthe extension 29 of the gearbox 15 and identical planet bevel gears 55,56 fixed on the radial output shafts 49, 50, respectively. Each planetbevel gear is engaged with the sun bevel gear 54 at right angle withone-to-one ratio. The horizontal transverse driving shaft 21 and theplanetary gearboxes 44, 45 can be disposed under the water level or overthe water level as in the previously described embodiment.

[0050] Two propelling means 57, 58 or 57′, 58′ are mounted on each ofthe planetary gearboxes 44 and 45, respectively, perpendicular to theradial output shaft to which they are affixed. The propelling means 57,58, 57′, 58′ include substantially flat propeller blades 57 a, 58 a, 57a′, 58 a′ which are balanced relative to the axes of rotation of theradial output shafts by a counter-weight 57 b, 58 b, 57 a′, 58 b′,respectively. The propeller blades are oriented substantially in theplanes of rotation around the radial output shafts. Preferably, theyhave an airfoil section in these planes. The gearbox 15 and theplanetary gearboxes 44, 45 can also be filled with a lubricating oil.

[0051] In the operation, the horizontal shaft 21 is rotated togetherwith the planetary gearboxes 44, 45 in the direction of arrow R by aninternal combustion engine 10 through the gearbox 15. The propellingmeans 57, 58 and 57′ 58′ are constrained by the planetary gearboxes 44,45 to rotate around the axes of the radial output shafts with therotational speed of the driving shaft 21. Two propelling means mountedon the same planetary gearbox are rotated in parallel planes in oppositedirections. The planes of rotation of the propelling means mounted onthe different planetary gearboxes are substantially perpendicular toeach other. The propeller blades 57 a, 58 a and 57 a′, 58 a′ areoriented so that during the rotations they do not interfere with eachother and with the gearbox 15 even if they are mounted in closeproximity with the gearbox 15.

[0052] During each 360 degrees turn of the horizontal shaft 21, fourpropulsion strokes are exerted which follow consecutively one afteranother. Each propulsion stroke is exerted by the movement of twopropeller blades 57 a, 58 a or 57 a′, 58 a′ when they are movingbackwards from the stern of the watercraft being oriented substantiallyperpendicular to such a movement. During the forward movement of thepropeller blades, they are oriented in the plane of such movement withminimum resistance in the water. If the driving shaft 21 and the rotatedplanetary gearboxes 44, 45 are disposed over the water level, thepropeller blades 57 a, 58 a, 57 a′ and 58 a′ are plunged into the waterfor exerting the propulsion force.

[0053] FIGS. 8-11 illustrate one more embodiment of a propulsionapparatus according to the present invention wherein a planetary gearbox59 is rotatably mounted on a support rod 60 which is fixed horizontallyto the transom 11 of a watercraft 12 on two brackets 61 and 62. As shownin FIGS. 9 and 10, the planetary gearbox 59 includes a housing 63 havinga central hub 64 (which can be made integrally with the housing) and acover 65. The support rod 60 extends through a sealing elements 66 and67 in the housing 63 and in the cover 65 of the planetary gearbox,respectively. The housing 63 encloses a planetary bevel gear engagementwhich includes a sun bevel gear 68 fixed on the support rod 60. Fouridentical bevel gears 69, 70, 71, 72 are fixed on the radial outputshafts 73, 74, 75, 76, respectively, and engaged with each other. Twoplanet bevel gears 77, 78 are fixed on the radial output shafts 73, 74,respectively, and are engaged with the sun bevel gear 68 with one-to-oneratio. Each of the radial output shafts 73, 74, 75, 76 is mounted in twobearings 79 and 80 and extends through the sealing elements 81 in thehousing 63. Four propelling means 82, 83, 84, 85 are affixed to the endsof the radial output shafts 73, 74, 75, 76, respectively, and disposedwith extensions in opposite directions perpendicular to the radialoutput shaft. The propelling means 82, 83, 84, 85 include the propellerblades 82 a, 83 a, 84 a, 85 a which are balanced by a counter-weight 82a, 83 b, 84 b, 85 b, respectively, relative to the axes of the radialoutput shafts. The planetary gearbox 59 are filled with a lubricatingoil.

[0054] In a preferred embodiment of such a propulsion apparatus, theplanetary gearbox is rotated by an outer rotor type brushless electricmotor. Two casings 86, 87, made from a non magnetic material, such asaluminum, are mounted on the support rod 60 with ability to be rotatedin the bearings 88, 89 and are fixed to the housing 63 and the cover 65of the planetary gearbox 59, respectively. A plurality of permanentmagnets 90 are disposed along the inner periphery of the casings andform the outer rotors.

[0055] Two inner stators 91, 92 are secured to the support rod 60 andcan be of any conventional type. Preferably, the inner stators 91, 92can be manufactured from laminated ferromagnetic material. As shown inFIG. 11, a plurality of protrusions 93 disposed radially around thesupport rod 60 are serving as cores for electric coils 94 which areconnected electrically to a battery or any other source of electricpower. There are axial holes 95, 96, radial holes 97, 98 in the supportrod 60 and also the longitudinal passages 99, 100 in the supportbrackets 61, 62, respectively, to allow the terminal leads of theelectric coils 94. The outer periphery of the protrusions 93 faces theinner periphery of the permanent magnets 90 across a small air gap 101.The inner stators 91, 92 generate a rotating electromagnetic fieldenabling to rotate the planetary gearbox 59 through the outer rotorswherein the casings 86, 87 work like a kind of hollow driving shafts.

[0056] During the operation, the planetary gearbox 59 is rotated in thedirection of an arrow R. The propeller blades 82 a, 83 a, 84 a and 85 aare constrained by the planetary gearbox 59 to rotate simultaneouslyaround the axis of the support rod 60 and around the axes of the radialoutput shafts 73, 74, 75, 76 of the planetary gearbox 59 with the samerotational speed. The propeller blades adjacent to each other in theperpendicular planes are rotated in opposite directions (clockwise andcounter-clockwise) not interfering with each other. After each 90degrees of rotation of the gearbox 59, two propeller blades are orientedsubstantially downwards and are plunged into the water for exerting thepropulsive force, while the other two propeller blades are disposedsubstantially horizontally over the water level.

[0057] During each turn of the planetary gearbox 59, four propulsionstrokes are exerted which follow consecutively one after another. Eachpropulsion stroke is exerted by two propeller blades 82 a, 83 a or 84 a,85 a. Both sides of the blades are used consecutively as workingsurfaces. During backward movement astern, the propeller blades arealways oriented substantially perpendicular to such movement exertingthe propulsion force propelling the watercraft. The forward movingpropeller blades are always oriented in the plane of such movement withminimum resistance in the water. When the orientations of the blades arechanging from the horizontal to the downward position, thecircumferential velocity of their rotations around the axis of thedriving shaft is increased.

[0058] While this invention has been described with reference to thestructures disclosed herein, they are merely chosen and described toillustrate the principle, applications, and practical use of theinvention to thereby better enable others skilled in the art to utilizethis invention. The preferred embodiments of the present inventionillustrated in FIGS. 1-11 are not confined to the details as set forthand are not intended to be exhaustive or to limit the invention to theprecise form disclosed. For example, an embodiment of the propulsionapparatus described with electrical drive can be used with an internalcombustion engine or any other type of drive. The invention is intendedto cover any modifications, which may be variously practiced within thescope of the following claims or their legal equivalents, rather than byexamples given.

What is claimed is:
 1. A method of propelling watercraft, including:mounting at least two propelling means on a watercraft with ability tobe rotated around a transverse axis and around at least two radial axeswith the same speed; rotating said at least two propelling meanssimultaneously around said transverse axis and around said at least tworadial axes with the same speed, wherein: said transverse axis beingdisposed substantially perpendicular to the advancement direction ofsaid watercraft; said at least two radial axes being disposedsubstantially perpendicular to said transverse axis and can be rotatedtogether with said at least two propelling means around said transverseaxis; each of said at least two propelling means including at least onesubstantially flat propeller blade balanced relative to one of said atleast two radial axes so that the centers of gravity of said propellingmeans being disposed substantially on said radial axes.
 2. The method ofpropelling watercraft of claim 1, further including: disposing said atleast one substantially flat propeller blade substantially in plane ofsaid rotation around one of said at least two radial axes.
 3. The methodof propelling watercraft of claim 1, further including: disposing saidat least one substantially flat propeller blade at an acute angle withplane of said rotation around one of said at least two radial axes. 4.The method of propelling watercraft of claim 1, further including;mounting three said propelling means with ability to be rotated aroundsaid transverse axis and around three said radial axes; rotating each ofsaid three propelling means simultaneously around said transverse axisand around one of said three radial axes with the same speed, wherein:said three radial axes being disposed substantially 120 degrees fromeach other around said transverse axis.
 5. The method of propellingwatercraft of claim 1, further including: mounting at least two pairs ofsaid propelling means with ability to be rotated around said transverseaxis and around at least two pairs of said radial axes; rotating saidtwo pairs of said propelling means simultaneously around said transverseaxis and around said two pairs of radial axes with the same speed,wherein: each said pair of radial axes being disposed along one lineperpendicular to said transverse axis; said propelling means in eachsaid pair of propelling means being rotated in substantially parallelplanes; one said pair of propelling means being rotated in planes whichare substantially perpendicular to planes of rotation of another saidpair of propeller blades.
 6. The method of propelling watercraft ofclaim 5, wherein: said two pairs of radial axes being disposed along twointercrossed lines; said intercrossed lines being perpendicular to saidtransverse axis and to each other.
 7. The method of propellingwatercraft of claim 1, further including: disposing said transverse axison such a height over the water level that said propeller blades extendinto the water when they are oriented substantially downwards.
 8. Apropulsion apparatus for propelling watercraft, including: at least onedriving shaft disposed substantially perpendicular to the advancementdirection of said watercraft; at least one planetary gearbox mounted onsaid driving shaft and having at least two radial output shafts disposedsubstantially perpendicular to said driving shaft and constrained by aplanetary gear engagement to rotate with the speed of rotation of saiddriving shaft; means for rotating said planetary gearbox around the axisof said driving shaft, wherein: said at least one planetary gearboxincludes at least one sun bevel gear mounted coaxially with said drivingshaft and at least two planet bevel gears mounted on said at least tworadial output shafts; at least two propelling means mounted on said atleast two radial output shafts and disposed perpendicular to the axes ofrotation of said radial output shafts; each of said at least twopropelling means includes a substantially flat propeller blade which isbalanced relative to the axis of one of said radial output shaft so thatthe center of gravity of said propelling means been disposed on saidaxis of said radial output shaft.
 9. The propulsion apparatus of claim8, wherein: said substantially flat propeller blade is disposedsubstantially in plane of rotations of said propelling means around theaxis of one of said radial output shafts.
 10. The propulsion apparatusof claim 8, wherein: said propeller blade is disposed at acute anglewith plane of rotation of said propelling means around the axes of oneof said radial output shafts.
 11. The propulsion apparatus of claim 8,wherein: said driving shaft, said at least one planetary gearbox andsaid at least two propelling means are mounted on an outboard engine.12. The propulsion apparatus of claim 8, wherein: said driving shaft,said at least one planetary gearbox and said at least two propellingmeans are disposed on such a height over the water level that said atleast two propeller blades extend into the water when they are orientedsubstantially downwards.
 13. The propulsion apparatus of claim 8,wherein: said planetary gearbox includes three said radial output shaftdisposed substantially perpendicular to the axis of said driving shaftand substantially 120 degrees from each other.
 14. The propulsionapparatus of claim 8, wherein: two said planetary gearboxes are mountedon said driving shaft. each of said two planetary gearboxes includes twosaid radial output shafts disposed along a common axis perpendicular tothe axis of said driving shaft and two said propelling means mounted onsaid radial output shafts, wherein: said planes of rotations of saidpropelling means mounted on said radial output shafts of one of said toplanetary gearboxes are substantially perpendicular to said planes ofrotations of said propelling means mounted on said radial output shaftsof another said planetary gearboxes.
 15. A propulsion apparatus forpropelling watercraft, including: at least one support rod disposedsubstantially perpendicular to the advancement direction of saidwatercraft; at least one planetary gearbox mounted on said support rodwith ability to be rotated around the axis of said support rod, saidplanetary gear box having at least two radial output shafts disposedsubstantially perpendicular to said support rod, said radial outputshafts being constrained by planetary gear engagement of said planetarygearbox to rotate with the speed of rotation of said planetary gearbox;at least two propelling means affixed perpendicular to said two radialoutput shafts, said propelling means including substantially flatpropeller blades and counter-weights fixed on said propelling means andbalanced so that the centers of gravity of said propelling means beingdisposed on the axes of said radial output shafts, said propeller bladesbeing disposed substantially in planes of rotations of said propellingmeans around the axes of said radial output shafts.
 16. The propulsionapparatus of claim 15, wherein: four said radial output shafts beingdisposed along two intercrossed lines which are substantiallyperpendicular to the axis of said support rod and to each other, twopairs of said propelling means being mounted on said for radial outputshafts, wherein: said planes of rotations of one pair of said propellingmeans around said radial output shafts are substantially perpendicularto said planes of rotations of another pair of said propelling meansaround said radial output shafts. said planetary gearbox includes a sunbevel gear mounted on said support rod, at least one planet bevel gearengaged with said sun bevel gear and four identical bevel gears engagedwith each other.
 17. The propulsion apparatus of claim 15, wherein saidsupport rod is disposed substantially horizontally in such a height overthe water level that said fluid moving means extend into the water whenthey are orientated generally downwards.
 18. The propulsion apparatus ofclaim 15, wherein said planetary gearbox is rotated by an outer rotortype brushless electric motor, including: at least one inner statorsecured to said support rod; at least one outer rotor disposed coaxiallywith said support rod and secured to said planetary gearbox.
 19. Thepropulsion apparatus of claim 15, wherein: said inner stator includes aplurality of protrusions serving as cores for electrical coils;
 20. Thepropulsion apparatus of claim 15, wherein: said outer rotor comprises aplurality of permanent magnets disposed on inside surface of said outerrotor.